CVE-2021-20316
Publication date 23 August 2022
Last updated 24 July 2024
Ubuntu priority
A flaw was found in the way Samba handled file/directory metadata. This flaw allows an authenticated attacker with permissions to read or modify share metadata, to perform this operation outside of the share.
Mitigation
This issue can be mitigated by disabling SMB1, which is the default configuration in Samba 4.11 and above. In environments where SMB1 cannot be disabled, symlink support can be disabled with unix extensions = no.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| samba | 24.04 LTS noble |
Not affected
|
| 22.04 LTS jammy | Ignored | |
| 20.04 LTS focal | Ignored | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial |
Vulnerable
|
|
| 14.04 LTS trusty |
Vulnerable
|
Notes
mdeslaur
per upstream, fixing this required a whole rewrite of the VFS layer and there is no reasonable way to fix this in older versions. Marking this CVE as ignored for older releases.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
6.8 · Medium
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N |